Zhang Liang, Zhang Li, Ren Bo, Kang Xin, Zhang Xian, Zhao Zandong, Zheng Jiang
Sport Medicine Center, Honghui Hospital Affiliated with the School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Anesthesiology Department, Honghui Hospital Affiliated with the School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
J Int Med Res. 2020 Dec;48(12):300060520980593. doi: 10.1177/0300060520980593.
Meniscal injury is a common sports medicine condition. Magnetic resonance imaging (MRI) is widely used to effectively diagnose meniscal injury. A flag sign on MRI is usually typical of a meniscal root tear. We report the case of a "flag sign" caused by a free lateral meniscal fragment that mimicked the anterior cruciate ligament (ACL) signal on MRI.
This was a 21-year-old male patient who suffered a knee injury (swelling and pain) playing football. A physical examination revealed positive Lachman and lateral McMurray tests. MRI images showed an ACL injury and the flag sign, and a diagnosis of ACL tear and lateral meniscal injury was made. Arthroscopic lateral meniscal repair and ACL reconstruction were performed. Six months postoperatively, MRI showed that the injuries were well healed. In this particular case, the flag sign introduced interference to the MRI assessment of ACL injury.
This case illustrates that clinicians should carefully identify the morphological changes in the meniscus and the relationship of the meniscus with the femoral condyle before reaching a final diagnosis.
半月板损伤是一种常见的运动医学病症。磁共振成像（MRI）被广泛用于有效诊断半月板损伤。MRI上的旗征通常是半月板根部撕裂的典型表现。我们报告一例由外侧半月板游离碎片导致的“旗征”病例，该碎片在MRI上模仿了前交叉韧带（ACL）信号。
这是一名21岁男性患者，在踢足球时膝盖受伤（肿胀和疼痛）。体格检查显示拉赫曼试验和外侧麦克马瑞试验呈阳性。MRI图像显示ACL损伤和旗征，诊断为ACL撕裂和外侧半月板损伤。进行了关节镜下外侧半月板修复和ACL重建。术后六个月，MRI显示损伤愈合良好。在这个特殊病例中，旗征对ACL损伤的MRI评估产生了干扰。
该病例表明，临床医生在做出最终诊断前应仔细识别半月板的形态变化以及半月板与股骨髁的关系。
